Objective

This study is designed to explore the morphological changes of endothelial cells (ECs) under different levels of shear stress and find the effective evaluation indicators with in vivo and in vitro experiments.

Methods

Human umbilical vein endothelial cells (HUVECs) and Sprague–Dawley rats were used to study the effect of different shear stress which applied by means of parallel plate-flow chamber and abdominal aorta banding model on the morphology of endothelial cells. Then, fluorescence images were acquired by means of a confocal laser-scanning microscope. Finally, Cell morphological indicators were extracted by SRAD-MCW computer image processing algorithm for quantitative analysis.

Results

1) The morphological changes of HUVECs were observed after exposure to shear stress for 6 h, the HUVECs were elongated and spindle-shaped. And the degree of cell deformability was different while the exposure time was different, then it became stable after 18 h. The HUVECs exposure to high shear stress (HSS) exhibited an ordered cell arrangement, while the HUVECs exposure to low shear stress (LSS) showed a disordered cell arrangement. 2) Traditional cell morphological indicators such as area, perimeter, long axis diameter, short axis diameter and orientation angle were not significantly different between the normal shear stress (NSS) group and the LSS group (P > 0.05), but the intercellular space characteristics such as the junction length per unit area and the triple points per unit area were significantly different (P < 0.05).

Conclusion

These results demonstrate that the size and duration of shear stress can affect the morphology and arrangement of endothelial cells. The commonly used evaluation indicators for studying the effect of shear stress on the morphology of endothelial cells, including area, perimeter, long axis diameter, short axis diameter and orientation angle, etc., had no significant statistical significance, while the intercellular space characteristics including the junction length per unit area and the triple points per unit area can be used as effective indicator to study the effect of shear stress on the morphology of endothelial cells.

中文翻译：

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低壁剪应力对内皮细胞形态的影响及其评价指标

客观的

本研究旨在探讨不同剪切应力水平下内皮细胞（ECs）的形态变化，并通过体内外实验寻找有效的评价指标。

方法

以人脐静脉内皮细胞（HUVECs）和Sprague-Dawley大鼠为研究对象，研究了平行板流室和腹主动脉带模型施加的不同剪切应力对内皮细胞形态的影响。然后，通过共聚焦激光扫描显微镜获得荧光图像。最后通过SRAD-MCW计算机图像处理算法提取细胞形态学指标进行定量分析。

结果

1) 剪切应力作用 6 h 后观察 HUVECs 的形态变化，HUVECs 呈长纺锤形。暴露时间不同，细胞变形程度不同，18 h后趋于稳定。暴露于高剪切应力 (HSS) 的 HUVECs 显示出有序的细胞排列，而暴露于低剪切应力 (LSS) 的 HUVECs 显示出无序的细胞排列。2) 常规剪应力(NSS)组与LSS组的面积、周长、长轴径、短轴径、取向角等传统细胞形态学指标差异不显着( P> 0.05），但单位面积的连接长度和单位面积的三相点等细胞间空间特征存在显着差异（P < 0.05）。

结论

这些结果表明剪切应力的大小和持续时间可以影响内皮细胞的形态和排列。研究剪切应力对内皮细胞形态影响的常用评价指标，包括面积、周长、长轴直径、短轴直径和取向角等，均无显着统计学意义，而细胞间隙特征包括单位面积的连接长度和单位面积的三相点可作为研究剪切应力对内皮细胞形态影响的有效指标。